(A) General EPSC standards. MSD shall review all EPSC plans for compliance with the following general standards and review criteria:
(1) Overall design goal. A design removal efficiency goal of 80% for total suspended solids from land disturbing activities shall be applied to the design, review, and approval of EPSC plans. The following structural and non-structural standards are to be utilized to achieve this goal.
(a) Compliance with MSD Design Manual, Standard Specifications and Standard Drawings. Except where innovative or alternative management practices are approved pursuant to subsection (A)(2) below, all EPSC measures shall be designed and installed in accordance with the specifications contained in the MSD Design Manual, Standard Specifications and Standard Drawings, as it may be revised from time to time, which is hereby incorporated by reference into this chapter.
(b) Non-structural site management practices. Non-structural site management practices to prevent erosion and minimize sediment discharge shall be considered in MSD's evaluation of subsection (A)(1) above. Such practices may include the following standards:
1. Minimize site disturbance to preserve and maintain existing vegetative cover;
2. Limit the number of temporary access points to the site for land disturbing activities;
3. Phase and sequence construction activities;
4. Locate temporary and permanent soil disposal areas, haul roads and construction staging areas to minimize erosion, sediment transport and disturbance to existing vegetation.
(c) Attainment of design goal not practicable. Where attainment of this design removal efficiency goal through the use of structural and non-structural measures is not practicable, the Permittee shall submit written justification to MSD for review and approval.
(2) Alternative management practices. To encourage the development and testing of alternative EPSC measures, alternative management practices that are not included in the MSD Design Manual, Standard Specifications and Standard Drawings may be allowed upon review and approval of MSD.
(a) A permittee seeking to use an alternative management practice shall concurrently submit substantial evidence that the proposed measure will perform at least equivalent to a currently approved control contained in the MSD Design Manual, Standard Specifications and Standard Drawings. Evidence may include, but is not limited to, peer-review by a panel of registered professional engineers and research results as reported in professional journals or other literature.
(b) If MSD finds the control or practice has failed or is inadequate to contain sediment onsite, the permittee shall remove and replace it with a control approved by MSD and found in the MSD Design Manual, Standard Specifications and Standard Drawings.
(B) Specific EPSC standards. MSD shall review all EPSC plans for compliance with the following specific standards and review criteria:
(1) Sediment tracking control. Stabilized construction entrances shall be located and utilized at all points of ingress/egress on a construction site. The transfer of soil, mud and dust onto public rights-of-ways shall be prevented.
(2) Construction dewatering operations. Whenever construction dewatering operations are required on a site, they shall be conducted according to the specifications set forth in the MSD Design Manual, Standard Specifications and Standard Drawings.
(3) Crossing of waterways. Crossings of waterways during construction shall be minimized and approved by MSD. Encroachment into stream buffers, riparian areas and wetlands shall be avoided.
(4) Topsoil. Topsoil shall be stockpiled and preserved from erosion or dispersal both during and after site grading operations.
(5) Temporary stabilization measures.
(a) Where construction or land disturbance activity will or has temporarily ceased on any portion of a site, temporary site stabilization measures shall be required as soon as practicable, but no later than 14 calendar days after the activity has ceased. Permanent or temporary stabilization shall be completed within:
1. Fourteen calendar days for the surface of all perimeter dikes, ditches, swales, perimeter slopes, and all slopes greater than 3 horizontal to 1 vertical (3:1);
2. Fourteen calendar days as to all other disturbed or graded areas on the project site.
(b) The requirements of subsections (B)(5)(a)1. and (B)(5)(a)2. do not apply to those areas which are shown on the plan and currently being used for material storage or for those areas on which construction activities are currently being performed or to prepared structural subgrades, provided that structural EPSC measures remain in place.
(6) Final stabilization. Final stabilization of the site shall be required within 14 calendar days of construction completion.
(7) Temporary structural controls. Temporary structural controls installed during construction shall be designed to accomplish maximum stabilization and control of erosion and sedimentation, and shall be installed, maintained, and removed according to the specifications set forth in the MSD Design Manual, Standard Specifications and Standard Drawings. All temporary structural controls shall function as designed when controlling the peak runoff resulting from the storm event identified in the MSD Design Manual, Standard Specifications and Standard Drawings.
(8) Permanent structural controls. All permanent structural controls, including drainage facilities such as channels, storm sewer inlets, and detention basins, shall be designed according to the standards set forth in the MSD Design Manual, Standard Specifications and Standard Drawings.
(1994 Jeff. Code, § 159.03) (Jeff. Ord. 28-2000, adopted and effective 11-21-2000; Jeff. Am. Ord. 26-2001, adopted and effective 9-25-2001; Lou. Metro Am. Ord. No. 186-2007, approved 10-1-2007)